When Manchester City were last top of the Premier League, they displayed the table on the screens at Eastlands, superimposed in front of a "blue moon rising" with the club's old battle hymn playing in the background.

Significantly, this time they made very little fuss. In January, when they clambered to the summit after a 4‑3 win over Wolverhampton Wanderers conjured by Carlos Tevez, everyone at Eastlands knew it was unlikely to last. Manchester United had a fistful of games in hand and were playing the next day. It was a bit of a tease.

Now it is for real. On Sunday Manchester City go to Old Trafford top of the league and should they force a draw – something, admittedly, no side since West Bromwich Albion 12 months ago have managed – they will stay there.

Tevez is now a non-person at Manchester City. Before Roberto Mancini addresses any kind of press conference there is an announcement that he will not take any questions on the man who was once his captain and the public face of the club.

However, he was mentioned, if only by implication, when the Manchester City manager remarked how well Mario Balotelli had adapted to being consigned to the bench in the wake of Sergio Agüero's arrival.

He had not behaved like a Roman emperor on being told the palace kitchens were fresh out of larks tongues in aspic. He had knuckled down and the overhead kick that opened up Aston Villa's defence for the first but not the last time was his fourth goal in as many matches.

This was Alex McLeish's first league defeat as Villa manager and for a man who once competed with Alan Hansen for the title of Scotland's finest defender its manner was galling. "We were amateur," was the withering verdict on his back four.

There are several ways to win a championship. Sir Alex Ferguson's preferred method is to keep in touch with the leaders until the end of the group phase of the Champions League and then accelerate away into the long winter nights. Mancini won Serie A twice conventionally with Internazionale and on both occasions his side took the lead early and kept it.

"It is important for the fans that we are top," he said. "It is correct, it is right for them to be excited. We have worked for this and we want to stay here a long time."

Not since March 1968 when City won 3-1 at Old Trafford has the Manchester derby been fought out between two teams competing so directly for the championship but the encounter with Villarreal on Tuesday night almost matches it for importance.

Villarreal will not defend as ineptly as Aston Villa and while Manchester City could probably afford to lose to United, defeat to La Liga's Yellow Submarines might be terminal.

Mancini went back to his time in Italy for guidance. City have not started well in the Champions League but neither had Inter in 2006 when they lost their opening matches to Sporting Lisbon and Bayern Munich and still squeezed through.

Mancini said that it could go the other way. Eight years ago, he was in charge of another team that played in sky blue but, unlike Manchester City, Lazio were a selling club, forced to offload Hernán Crespo and Alessandro Nesta and impose savage pay cuts.

He remarked that Lazio had taken four points from their opening two group games and then collapsed tosuch an extent that they finished last, beaten 4-0 in the Stadio Olimpico by Chelsea.

"We know we need more experience in this competition," said Mancini. "We have improved a lot in the Premier League and now we need to improve in the Champions League. We must understand that if you cannot win a game, you must not lose it."